Deburring Tool

ABSTRACT

A deburring tool has a hollow top portion having an interior conical surface and an exterior surface. The exterior surface of the deburring tool is preferably conical. The top portion has a plurality of flutes formed therein and extending between the interior and exterior surfaces. Each of the flutes has a cutting edge formed at the interior conical surface. In operation, rotation of the deburring tool about a longitudinal axis removes burrs projecting from bar stock contacting the interior conical surface. A method of deburring bar stock comprises: (a) rotating the deburring tool about a longitudinal axis, and (b) contacting the bar stock to the deburring tool interior conical surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/953,373 filed on Nov. 29, 2015, entitled “Deburring Tool” whichclaims priority benefit from International Application No.PCT/US2014/040096 filed on May 29, 2014, entitled “Deburring Tool” whichin turn claimed priority from U.S. application Ser. No. 61/956,039 filedon May 31, 2013, also entitled “Deburring Tool”. This application isalso related to and claims priority benefit from the '096 and'039applications. The '373, '096 and '039 applications are herebyincorporated by reference herein in their entireties.

With respect to the above-mentioned parent application, to the extentany amendments, characterizations or other assertions previously made inany such related patent applications or patents, including any parent,co-pending or continuing application with respect to any art, prior orotherwise, could be construed as a disclaimer of any subject mattersupported by the disclosure of the present application, such disclaimeris hereby rescinded and retracted. Prior art previously considered inany related patent application(s) or patent(s), including any parent,co-pending or continuing application, should be reconsidered withrespect to the subject matter being claimed in the present application.

FIELD OF THE INVENTION

The present invention relates to deburring tools. In particular, thepresent invention relates to a tool that can be attached to a handhelddrill and used to deburr bar stock.

BACKGROUND OF THE INVENTION

Burrs, raised or frayed edges of material often result from machiningoperations such as grinding, drilling, milling, engraving, and turning.In many cases, it is necessary or preferred to remove these burrs, aprocess known as deburring, as the presence of burrs can lead toincreased wear on the parts involved, leading to frequent replacement,or even preventing the parts from working as intended.

Burrs formed in drilled holes can cause fastener and material problems.Burrs can lead to concentrated stress at the edges of holes, therebydecreasing the material's resistance to fracture. Burrs also increasethe friction and heat between moving parts. In addition, burrs caninterfere with the proper placement of fasteners, and can also lead tocorrosion. Furthermore, the sharp edges of many burrs tend toconcentrate electric charge and can lead to spontaneous electronicdischarge.

One technique for removing burrs, known as manual deburring, involvesthe use of a handheld tool, such as a power drill, to remove the burrs.The tool can be a file, grinding disk, grinding stone, grinding tool,sand paper, or the like which is used to file down the burrs. Manualdeburring is often time and labor intensive.

In many instances, deburring accounts for a large amount ofmanufacturing costs. In addition to manual deburring, there arecurrently several deburring processes including: mass-finishing, spindlefinishing, media blasting, sanding, grinding, wire brushing, abrasiveflow machining, electrochemical deburring, electropolishing, thermalenergy method, machining, and cryogenic. Unfortunately these processesare either expensive, messy, and/or require large equipment.

What is needed is a way to deburr that is more efficient than currentmanual deburring methods, but does not require the expensive equipmentand/or materials of today's current deburring processes such as millbastard files, grinders, and sanders. It would also be beneficial ifthis method could be conducted solely using a handheld power drill,without the need of a vice.

SUMMARY OF THE INVENTION

A deburring tool is designed to be used in a handheld power drill andreduces or eliminates the need for cumbersome tools and equipment. Thedeburring tool can reduce the time spent deburring and increaseefficiency in the work place and in the field.

The deburring tool is configured to make dressing the end cut of barstock resulting from manufacturing, machining or milling. Furthermorethe deburring tool performs in a wide range of applications including,but not limited to, anchors, bolts, fasteners, pins, and rods, tubingand pipes and other devices manufactured, machined, or milled from barstock.

In some embodiments the deburring tool is a solid machined tool cut froma solid tool steel bar, although other materials can be handled as well.The deburring tool has a cone-shaped chamber and a number of flutes witha cutting edge determined by the size of the tool and its particularuse. The length, size and shape of the flutes and the cutting edge canalso be configured to the size of the cone chamber and its designedapplication. The conical shape of the cutting chamber accommodates barstock of various sizes and shapes. For example, the same conical-shapeddeburring tool described herein could accept for deburring threadedcylindrical bar stock of varying diameters, such as one-eighth inch(0.3175 centimeters) and one-fourth inch (0.635 centimeters).

In some embodiments, the proportions of the cone body, the cone toolface, the flutes, the flute cutting edge, the internal chamfer, theexternal chamfer, the radius, the relief portion of the flute, the conebase, the tool shaft portion, the shaft grip surface and the relief cutfor tool engagement are engineered to make the tool convenient to usewith a handheld drill.

In a preferred embodiment, a deburring tool comprises a hollow topportion having an interior conical surface and an exterior surface. Thetop portion has a plurality of flutes formed therein, which extendbetween the interior and exterior surfaces. Each of the flutes has acutting edge formed at the interior conical surface. In operation,rotation of the deburring tool about a longitudinal axis removes burrsprojecting from bar stock contacting the interior conical surface.

The exterior surface of the deburring tool is preferably conical. Thetop portion preferably has three flutes formed therein. Each of theflutes is preferably offset from the top portion longitudinal axis by0.050 inch (0.127 cm). The cutting edge and the interior conical surfacepreferably form an angle between 10 and 20 degrees.

The deburring tool preferably further comprises a tool shaft portionextending downwardly from the hollow top portion. The tool shaft portionis preferably configured for attachment to a drill. The tool shaftportion is preferably hexagonal in cross-section.

The deburring tool is preferably configured to deburr bar stock having across-sectional profile selected from group consisting of round, square,triangular, rectangular, pentagonal, hexagonal, heptagonal andoctagonal. The deburring tool is preferably configured to deburr barstock having an exterior surface conformation selected from groupconsisting of smooth, threaded, knurled, knobby, pocked and serrated.

The deburring tool is preferably formed of steel.

A preferred method of deburring bar stock comprises:

-   -   (a) rotating a deburring tool about a longitudinal axis, the        deburring tool comprising a hollow top portion having an        interior conical surface and an exterior surface, the top        portion having a plurality of flutes formed therein and        extending between the interior and exterior surfaces, each of        the flutes having a cutting edge formed at the interior conical        surface; and    -   (b) contacting the bar stock to the deburring tool interior        conical surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of the present deburring tool.

FIG. 2 is a bottom view of the deburring tool of FIG. 1.

FIG. 3 is a top view of the deburring tool of FIGS. 1 and 2.

FIG. 4 is a side view of the deburring tool of FIGS. 1-3 depicting theoffset of the flutes from the longitudinal of the shaft and the angle ofthe flutes.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

FIG. 1 shows a perspective view of deburring tool 10. Deburring tool 10has tool shaft portion 18 and conical top portion 30.

Conical top portion 30 is made up of internal cone surface 23 a andexternal cone surface 23 b which are capped by tool face 15. Tool face15 is connected to internal cone body 23 a and external cone body 23 bvia internal chamfer 14 and external chamfer 16, respectively. A collarportion 27 interconnects external chamfer 16 and external cone body 23b.

Conical top portion 30 has formed therein at least one flute 13 havingat least one cutting edge 12. Conical top portion 30 also has at leastone relief portion 22 associated with flute 13. In the particularembodiment shown, conical top portion 30 has three flutes 13. However,other embodiments can employ various numbers of flutes 13 withcorresponding cutting edges 12 and relief portions 22, depending uponthe nature of the bar stock to be deburred.

Conical top portion 30 attaches to tool shaft portion 18 at junction 17.In some embodiments, conical top portion 30 need not be perfectlyconical. For example, external cone surface 23 b could extend outwardlyin quasi-cylindrical fashion, so long as flutes 13 remained open betweeninternal surface 23 a and external surface 23 b such that deburredmaterial from the work piece ejects away from deburring tool 10.

Tool shaft portion 8 includes shaft grip surface 11, shown as beinghexagonally shaped in FIG. 1, to allow for convenient handling andattachment. A rounded portion 19 is formed at the upper end of eachshaft grip surface 11. Tool shaft portion 18 can also have a reliefportion 21 which is configured to connect the deburring tool 10 with apower drill (not shown).

When in use, deburring tool 10 is connected to a drill and rotateseither counter-clockwise (or clockwise) depending on the nature of thebar stock being deburred and the configuration of flutes 13. Cuttingedge 12 then cuts the burrs from the end of the bar stock.

In one example, the bar stock is a continuous threaded rod that containsa number of burrs remaining from a prior cutting operation. Inoperation, interior cone surface 23 a of deburring tool 10 faces the endof the rod with the burrs to be removed. Deburring tool 10 deburrs thethreaded rod without damaging the threads, so that a nut can be spunonto the rod without further preparation.

FIGS. 2 and 3 show bottom and top views, respectively, of deburring tool10, as described above with respect to FIG. 1.

FIG. 4 shows deburring tool 10 with flute 13, which forms a flute angleA with respect to longitudinal axis L of tool shaft portion 18. FIG. 4also depicts flute 13 positioned a distance defined by flute offset Bfrom longitudinal axis L. Distance C is the distance between tool face15 and the junction of collar portion 27 and external cone body 23 b. Ina preferred embodiment, distance C is approximately 0.130 inch (0.330centimeters). Distance R is the radial distance of each of theoppositely disposed semicircular portions of flute 13. In a preferredembodiment, distance R is preferably approximately 0.063 inch (0.160centimeters). Distance D is the distance between the center points ofthe oppositely disposed semicircular portions of flute 13. In apreferred embodiment, distance D is approximately 0.520 inch (1.321centimeters).

In preferred embodiments, flute angle A is approximately 10-20 degreesfrom vertical A. Flute offset B is approximately 0.030-0.050 inch(0.076-0.127 centimeter) off-center from the longitudinal axis of shaftportion 8. Forming deburring tool 10 with these measurements makes iteasier to use deburring tool 10 with a hand drill, as tool 10 will onlybite 0.0015 inch (0.0038 centimeter) per revolution. This amount of biteis conducive for using deburring tool solely with a power drill andwithout the use of a vice to secure the bar stock.

In preferred embodiments, flute angle A is the same for each of flutes13, and flute offset B is the same for each of flutes 13.

Table 1 sets forth experimental data with performance characteristics ofdeburring tool 10 using various measurements for flute angle A and fluteoffset B.

TABLE 1 Flute Flute Offset Angle (inch/cm) Result 10° 0.000/0.000Substantial pressure required; small chips produced; work materialhardening occurred 10° 0.020/0.051 Substantial pressure required; smallchips produced 10° 0.040/0.102 Substantial pressure required; moderatesize chips produced 15° 0.020/0.051 Medium pressure required; smallchips produced 15° 0.040/0.102 Medium pressure required; insufficientmaterial removed 15° 0.050/0.127 Little pressure required to hold workpiece; work piece does not twist out of hand; free milling 15°0.060/0.152 Little pressure required; work piece twists in hand; bearingsurface minimal 20° 0.000/0.000 Moderate pressure required; small chipsproduced; work material hardening occurred 20° 0.020/0.051 Less pressurerequired; small chips produced 20° 0.040/0.102 Less pressure required;grabs work; small bearing surface

While particular elements, embodiments and applications of the presentinvention have been shown and described, it will be understood, that theinvention is not limited thereto since modifications can be made withoutdeparting from the scope of the present disclosure, particularly inlight of the foregoing teachings.

What is claimed is:
 1. A deburring tool comprising a hollow top portionhaving an interior conical surface and an exterior conical surface, saidtop portion having: (a) a tool face; (b) a longitudinal axis; and (c) anexactly three flutes formed therein extending between said interior andexterior surfaces, each of said flutes having a cutting edge formed atsaid interior conical surface, said cutting edge forming an angle asmeasured from said longitudinal axis of said top portion, wherebyrotation of said deburring tool about said longitudinal axis removesburrs projecting from bar stock contacting said interior conicalsurface.
 2. The deburring tool of claim 1, wherein each of said fluteshas an oblong configuration with oppositely disposed semicircular topand bottom end portions.
 3. The deburring tool of claim 2, wherein thedistance between a center point of each said semicircular top endportions and a center point of each said semicircular bottom endportions is approximately 0.520 in (1.321 cm).
 4. The deburring tool ofclaim 2, wherein each of said semicircular top end portions terminatethe same distance from said tool face and each of said semicircularbottom end portions terminate the same distance from said tool face. 5.The deburring tool of claim 2, wherein each of said semicircular bottomend portion of said flutes has a center of curvature that is offset fromsaid longitudinal axis by 0.050 inch (0.127 cm).
 6. The deburring toolof claim 1, wherein said cutting edge and said interior conical surfaceform an angle between 10 and 20 degrees.
 7. The deburring tool of claim1, further comprising a tool shaft portion extending downwardly fromsaid hollow top portion, said shaft portion having a longitudinal axiscoextensive with said top portion longitudinal axis.
 8. The deburringtool of claim 7, wherein said tool shaft portion is configured forattachment to a drill.
 9. The deburring tool of claim 7, wherein thecross-section of said tool shaft portion is hexagonal.
 10. The deburringtool of claim 1, wherein said deburring tool is configured to deburr barstock having a cross-sectional profile selected from the groupconsisting of round, square, triangular, rectangular, pentagonal,hexagonal, heptagonal and octagonal.
 11. The deburring tool of claim 1,wherein said deburring tool is configured to deburr bar stock having anexterior surface conformation selected from the group consisting ofsmooth, threaded, knurled, knobby, pocked and serrated.
 12. A deburringtool comprising a hollow top portion having an interior conical surfaceand an exterior conical surface, said top portion having: (a) a toolface; (b) a longitudinal axis; and (c) a plurality of flutes formedtherein extending between said interior and exterior surfaces, each ofsaid flutes having a top end and a bottom end, wherein each of said topends terminate the same distance from said tool face and each of saidbottom ends terminate the same distance from said tool face, each ofsaid flutes having a cutting edge formed at said interior conicalsurface, said cutting edge forming an angle as measured from saidlongitudinal axis of said top portion, whereby rotation of saiddeburring tool about said longitudinal axis removes burrs projectingfrom bar stock contacting said interior conical surface.
 13. Thedeburring tool of claim 12, wherein the distance between a center pointof each said top ends and a center point of each said bottom ends isapproximately 0.520 in (1.321 cm).
 14. The deburring tool of claim 12,wherein each of said bottom end of said flutes has a center that isoffset from said longitudinal axis by 0.050 inch (0.127 cm).
 15. Thedeburring tool of claim 12, wherein said cutting edge and said interiorconical surface form an angle between 10 and 20 degrees.
 16. Thedeburring tool of claim 12, further comprising a tool shaft portionextending downwardly from said hollow top portion, said shaft portionhaving a longitudinal axis coextensive with said top portionlongitudinal axis.
 17. The deburring tool of claim 16, wherein said toolshaft portion is configured for attachment to a drill.
 18. The deburringtool of claim 16, wherein the cross-section of said tool shaft portionis hexagonal.
 19. The deburring tool of claim 12, wherein said deburringtool is configured to deburr bar stock having a cross-sectional profileselected from the group consisting of round, square, triangular,rectangular, pentagonal, hexagonal, heptagonal and octagonal.
 20. Thedeburring tool of claim 12, wherein said deburring tool is configured todeburr bar stock having an exterior surface conformation selected fromthe group consisting of smooth, threaded, knurled, knobby, pocked andserrated.